Substituted 4-phenoxyquinolines, such as those ##STR1## described in EP 326,330, are valuable plant fungicides. Compounds of this type have generally been prepared by condensing a substituted 4-haloquinoline with an excess of a substituted phenol, preferably by refluxing in xylene overnight. Even in refluxing xylene, however, the desired reaction is relatively sluggish, and it would be advantageous to be able to accelerate the rate of the reaction.